This invention relates to modular type electrical connectors for connecting wires in one group or bundle to the wires of a second group or bundle and to an improved apparatus for inserting the wires into the displation type contact terminals in the connector. The embodiment of the invention herein shown and described comprises a connector which is particularly intended for use in the telephone industry, however, other uses for the invention will be apparent to those skilled in the art.
The electrical cables used in telephone industry comprise a plurality of pairs of conductors which are contained in a suitable protective covering or sheath. The number of pairs in the cable may vary from a low of 25 to a high of about 3000 or more and it is frequently necessary to splice the ends of two cable sections by electrically connecting the individual wires in one of the cable ends to the wires in the other cable end.
Originally, the splicing operations were carried out by simply twisting the individual wires together but more recently connectors have been used for this purpose. Individual connectors are frequently used which connect two wires to each other so that in every splice, a number of connectors is required which is equal to the number of wires in one of the cables. Another type of connector which is now commonly used comprises an elongated connector module which has a plurality of contact terminals therein, each such terminal device being adapted to receive and connect two wires to each other. Modular connectors are frequently manufactured with 50 or more terminal devices therein so that each modular connector is capable of making a like number, 50 or more, electrical connections for the wires in the cable ends. A plurality of such modular connectors are thus required for a cable having a large number of pairs but the number of connectors required is substantially reduced as compared with individual discrete connectors.
Both types of connectors, modular and discrete, are widely used in the telephone industry and each has certain advantages for particular splicing problems.
Modular type connectors and wire insertion apparatus for telephone cable splicing are shown, for example, in U.S. Pat. Nos. 3,459,878, 3,611,264, 3,772,635 3,708,779 and in application Ser. No. 630,589 filed Oct. 10, 1975. U.S. Pat. No. 3,866,293 also has some pertinence to the instant invention. Several of these devices have found widespread acceptance in the industry, however, past experience with these previously known types of mudular connectors, and particularly, insertion tools has revealed that they lack one or more features which would be highly desirable. For example, in most of, if not all of, these known types of apparatus, a large number of wires are simultaneously inserted into the terminals of the connector so that a relatively high force is required for the inserter. This requirement of a high insertion force in turn leads to a requirement that a manually operated insertion tool have a force multiplying means or to the requirement of a tool having a pneumatic or other powered actuator. It would be desirable to avoid both of these requirements if possible. Additionally, presently available tools usually have one or more subassemblies which must be mounted on, and removed from, the tool frame by the technician during a splicing task and it would be desirable to avoid the necessity of removing parts from the apparatus. The steps of removing parts of the apparatus, such as the wire guide or the insertion head, are very inconvenient to a technician working in the cramped quarters of a manhole and the tool parts are subject to damage while so removed from the frame.
The instant invention avoids the shortcomings discussed above and others in that the apparatus, which is mechanically relatively simple, does not have removable parts although it has the capability of carrying out all of the operations of the prior art devices. Specifically, an apparatus in accordance with the invention has a wire positioner which is permanently mounted on the frame but which can be swung from its normal operative position to permit movement of the wire inserter over the connector. The inserter itself comprises a roller which moves across the surface of the connector and successively engages the individual wires and inserts them into the terminals one after another. The amount of force required to move the inserter across the connector is quite low because of the fact that the wires are inserted individually, rather than simultaneously, and the inserter can be operated manually without undue fatigue.
It is accordingly an object of the invention to provide an improved apparatus for connecting groups of wires to each other. A further object is to provide an improved cable splicing apparatus. A still further object is to provide a cable splicing apparatus which can be manually operated without undue fatigue. A further object is to provide an apparatus which is of relatively simple construction, and which can be operated without a high degree of training on the part of the technician. A further object is to provide an improved modular type electrical connector.